tx,
What does your centershot look like? If your centershot is off to the left,it can cause this type of thing to happen.Move your rest and see what happens.
Your yard might very well be off.It sounds funny but if you are not using a level, you will start leveling off the yard and if their is a slant to it,there could be the reason your arrows impact to the left.Just something else to consider.
If it is a grip problem,a new bow could really help,if the grip on the new bow is designed better.Smaller is usually better in this case.
BUT without seeing you shoot and seeing your setup,it may be impossible to tell for sure.